US10342670B2ExpiredUtilityA1

Intervertebral prosthetic disc

72
Assignee: DE VILLIERS MALANPriority: May 27, 2003Filed: Apr 11, 2008Granted: Jul 9, 2019
Est. expiryMay 27, 2023(expired)· nominal 20-yr term from priority
Inventors:Malan De VilliersUlrich Hahnle
A61F 2002/30052A61F 2002/3008A61F 2002/30462A61F 2002/30904A61F 2310/0088A61F 2002/443A61F 2220/0075A61F 2230/0071A61F 2250/0045A61F 2220/0025A61F 2310/00029A61F 2/30771A61F 2310/00023A61F 2002/30405A61F 2002/30899A61F 2310/00604A61F 2002/30574A61F 2002/30884A61F 2002/30663A61F 2/4425A61F 2310/00179A61F 2002/30662A61F 2250/0098A61F 2220/0033A61F 2002/30649A61F 2002/30331A61F 2002/30054A61F 2/44A61F 2/4611
72
PatentIndex Score
3
Cited by
521
References
44
Claims

Abstract

A prosthetic disc for insertion between adjacent vertebrae includes upper and lower plates, a core disposed between the plates, and at least one projection extending from at least one of the upper and lower curved surfaces of the core into at least one recess of one of the inner surfaces of the plates. The recess is oversize with respect to the projection to allow sliding movement of the plate over the core while retaining the core between the plates during such sliding movement. The projection(s) may include a rod extending through an axial hole in the core, multiple surface features of the core, or the like.

Claims

exact text as granted — not AI-modified
What is claimed is: 
     
       1. An intervertebral prosthetic disc for insertion between adjacent vertebrae, the disc comprising:
 upper and lower plates having outer surfaces locatable against the respective vertebrae, inner bearing surfaces, and lateral portions; 
 a single monolithic core between the plates, the core having upper and lower surfaces complementary in shape to the inner bearing surfaces of the plates to allow the plates to slide over the core upon implantation between the adjacent vertebrae; 
 formations on at least one of the bearing surfaces of the plates and on the core which cooperate with one another to retain the core between the plates when the plates slide over the core, such formations including a rib on at least one of the plates and a channel in the core, wherein the rib is located within the channel to hold the core captive between the plates when the plates slide over the core, and wherein the rib and channel are located between a central axis of the core and an outer periphery of the plates; 
 wherein the channel is located in a spherically curved surface of the core; 
 wherein the rib has side surfaces located substantially at right angles to the inner bearing surface on which the rib is located; and 
 wherein the bearing surface of the plate at least partially surrounds the rib extending from the bearing surface. 
 
     
     
       2. The prosthetic disc of  claim 1 , wherein the rib is located with clearance in the channel. 
     
     
       3. The prosthetic disc of  claim 2 , wherein at a limit of sliding movement of the plates over the disc, the rib abuts against the channel. 
     
     
       4. The prosthetic disc of  claim 1 , wherein the inner bearing surfaces are curved surfaces. 
     
     
       5. The prosthetic disc of  claim 4 , wherein the upper and lower surfaces of the core are convex surfaces. 
     
     
       6. The prosthetic disc of  claim 1 , wherein the rib extends from the bearing surface in a direction substantially perpendicular to the bearing surface. 
     
     
       7. The prosthetic disc of  claim 1 , wherein the upper and lower plates comprise titanium with inner bearing surfaces of cobalt chromium molybdenum. 
     
     
       8. The prosthetic disc of  claim 7 , wherein the core comprises polyethylene. 
     
     
       9. The prosthetic disc of  claim 1 , further comprising at least one fin extending from the outer surfaces of the upper and lower plates. 
     
     
       10. A method of retaining a core in a prosthetic disc, the method comprising:
 providing upper and lower plates and a core, wherein the core has at least one convex bearing surface configured to slide over a corresponding bearing surface of one of the upper and lower plates upon implantation between adjacent vertebrae; 
 providing a rib on only one of the upper and lower plates and a channel in a corresponding bearing surface of the core, with the rib located between a central axis of the plate and an outer periphery thereof; 
 positioning the core between the upper and lower plates along the central axis of the plate, wherein the central axis of the plate is located midway between lateral edges of the prosthetic disc when the upper and lower plates and core are aligned vertically with one another; and 
 holding the core captive between the plates while the plates slide over the core by locating the rib within the channel. 
 
     
     
       11. The method of  claim 10 , wherein the upper and lower plates are allowed to slide over the core. 
     
     
       12. The method of  claim 10 , wherein the core comprises at least one spherical surface. 
     
     
       13. The prosthetic disc of  claim 1 , wherein the rib extends into the core and does not extend through the core. 
     
     
       14. The prosthetic disc of  claim 1 , wherein the rib extends outward from the at least one of the plates in a direction toward the other one of the plates. 
     
     
       15. The method of  claim 10 , wherein the core slides on a bearing surface of the at least one plate and the rib extends from the bearing surface toward the other one of the plates. 
     
     
       16. The prosthetic disc of  claim 1 , wherein at least one of the plates is free to rotate with respect to the core. 
     
     
       17. The method of  claim 10 , wherein the bearing surface of the plate at least partially surrounds the rib extending from the bearing surface. 
     
     
       18. The method of  claim 10 , wherein the rib extends into the core and does not extend through the core. 
     
     
       19. The prosthetic disc of  claim 1 , wherein the core comprises a low friction material to allow the plates to slide over the core. 
     
     
       20. The prosthetic disc of  claim 19 , wherein the core comprises a polyethylene, polymer or ceramic material. 
     
     
       21. The prosthetic disc of  claim 1 , wherein the core includes at least one spherical surface. 
     
     
       22. The method of  claim 10 , wherein the core comprises a low friction material to allow the plates to slide over the core. 
     
     
       23. The method of  claim 22 , wherein the core comprises a polyethylene, polymer or ceramic material. 
     
     
       24. The prosthetic disc of  claim 1 , wherein the rib side surfaces include two opposite side surfaces which are substantially parallel. 
     
     
       25. The prosthetic disc of  claim 1 , wherein the core comprises a polyethylene or ceramic material. 
     
     
       26. The prosthetic disc of  claim 21 , wherein the spherically curved surface of the core allows the core to rotate freely with respect to at least one of the plates. 
     
     
       27. The prosthetic disc of  claim 1 , wherein the central axis of the core is located midway between lateral edges of the prosthetic disc when the plates and core are aligned vertically with one another. 
     
     
       28. The prosthetic disc of  claim 26 , wherein the rib and channel do not intersect the central axis of the core when the plates and core are aligned vertically with one another. 
     
     
       29. The prosthetic disc of  claim 1 , wherein the rib side surfaces include two opposite side surfaces and wherein the bearing surface of the plate at least partially surrounds the two opposite side surfaces. 
     
     
       30. The prosthetic disc of  claim 1 , wherein the core is centered between lateral edges of the prosthetic disc when the plates bird core are aligned vertically with one another. 
     
     
       31. The prosthetic disc of  claim 1 , wherein the rib is a continuous annular rib. 
     
     
       32. The prosthetic disc of  claim 1 , wherein the rib is provided only on one of the plates. 
     
     
       33. The prosthetic disc of  claim 1 , wherein the rib is provided on both of the plates. 
     
     
       34. The prosthetic disc of  claim 1 , wherein the outer surfaces of the upper and lower plates are substantially planar. 
     
     
       35. The prosthetic disc of  claim 34 , wherein the substantially planar outer surfaces include fins, serrations or other surface features for promoting adhesion. 
     
     
       36. The method of  claim 10 , wherein the rib has side surfaces located substantially at right angles to a plate bearing surface on which the rib is located. 
     
     
       37. The method of  claim 36 , wherein the rib side surfaces include two opposite side surfaces which are substantially parallel. 
     
     
       38. The method of  claim 37 , wherein the plate bearing surface at least partially surrounds the two opposite side surfaces of the rib. 
     
     
       39. The method of  claim 10 , wherein the core comprises a polyethylene or ceramic material. 
     
     
       40. The method of  claim 10 , wherein the convex bearing surface of the core allows the core to rotate freely with respect to at least one of the upper and lower plates. 
     
     
       41. The method of  claim 10 , wherein the rib and channel do not intersect the central axis of the core when the upper and lower plates and core are aligned vertically with one another. 
     
     
       42. The method of  claim 10 , wherein the core is centered between lateral edges of the prosthetic disc when the upper and lower plates and core are aligned vertically with one another. 
     
     
       43. The method of  claim 10 , wherein the upper and lower plates have substantially planar outer surfaces. 
     
     
       44. The method of  claim 43 , wherein the substantially planar outer surfaces include fins, serrations or other surface features for promoting adhesion.

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